Virtual memory is something that more advanced users will likely be familiar with. It refers to using part of a hard drive as a scratch partition. This portion of the hard drive is sometimes called the page file, as well. This portion of the computer’s hard drive becomes part of the overall RAM available, expanding the power of the computer in this regard.
Remember that hard drives are much slower than the integrated circuits used for RAM. In the computer’s RAM hierarchy, this means that the hard drive will be de-prioritized and used to provide RAM when the other components are busy and access to them is slowed.